This is an excellent paper by by Kate G. Lindsay and Stephen A. Marshall, published in the Canadian Journal of Arthropod Indentification.
This is a key by Fritz Geller-Grimm & M. J. Smart . It covers the central European counterparts to our Choerades. This key is posted on Fritz Geller-Grimm's homepage on asilids.
Another illustrated key by Fritz Geller-Grimm. His key to Laphria is part of a much larger work on the robber flies of Germany.
Again a part of a larger work, covering all Australian robber flies, this time by Dr. Robert Lavigne.
Site in Japanese and English by Yuji Tagawa. Covers all Japanese Asilidae. Click on the subfamily Laphriinae to see photos of Choerades and Laphria s. lat. Extremely nice photos of pinned specimens.
Part of a larger site on robber flies and other insects in general. Lots of fantastic photos..
The section on robber flies is part of a larger site on butterflies, tiger beetles, and robber flies, with the overall title of "Wisconsin Butterflies." Again, the link is to the portion on the subfamily Laphriinae. Some excellent photos of live flies.
General Asilid Links
This is current principal site for Asilids on the web. It has sections on worker's addresses and e-mail, various translations, news, keys, fossils, photos, links and much more besides.
Other Useful Links
This is an excellent site for downloading free electronic copies of pre-1923 journal articles and books. The publications are available in PDF, DJVU, and several other formats. I prefer DJVU as for large papers it allows the smoothest scrolling, even on high-end machines (you can download a DJVU reader here). However, I often download the PDF version of an journal issue first, extract the article, and then convert it to a DJVU (you can download a PDF-to-DJVU converter here). I leave papers with just a few pages in PDF format, optimized to be compatible with Acrobat Ver. 4.0. That way, they will work on older computers. You can also use the site to search the hosted literature for references to a particular genus or species.
This site is an on-line, searchable list of all Diptera names. The information for each name includes its current validity. Very useful. The site is now overseen by Neal L. Evenhuis and Thomas Pape.
I've linked to this where appropriate in the North American Laphriini catalog, as well as in the species descriptions. Most of the Diptera types are well illustrated with several photographs each. Extemely useful.